The diagnostic utility of heart rate–corrected ST-segment depression during adenosine nuclear stress testing
Received 19 August 2009 published online 08 January 2010.
Abstract
Background
Vasodilator stress testing relies heavily on the imaging portion so that clinically useful information from the electrocardiogram may be overlooked. Stress-induced ST-segment depression, although uncommon, is highly predictive of severe disease. We investigated whether minor ST depressions during adenosine nuclear stress testing corrected for the modest heart rate increases (ST/HR slope and ST/HR index) might be clinically relevant.
Methods
The study included 74 consecutive patients with electrocardiograms interpretable for ischemia who underwent coronary angiography within the following 6 months.
Results
Abnormal responses using conventional thresholds for ischemic ST depression, the ST/HR slope, and ST/HR index were present in 8%, 20%, and 27%, respectively. The sensitivity for conventional ST depression was 11% and, when corrected for heart rate, increased to 27% and 36%, (P = .012), without adversely affecting the high positive predictive accuracy (83%, 80%, and 80%). Even with a normal perfusion scan, heart rate correction was highly predictive of multivessel coronary artery disease (4/5 patients).
Summary
Heart rate correction of ST depression during adenosine nuclear stress improves on conventional ST depression and may compliment perfusion imaging in detecting multivessel disease.
ABSTRACT